Nucleic acids and proteins during development of leaves of festuca pratensis

Abstract

Two developmental systems for leaves of Festuca pratensis were compared, namely development along the leaf (base to apex) and development of the whole leaf with time. The methods for examination of nucleic acids from leaves of F. pratensis were optimised and the changes occurring in rRNA fractions, tRNAs and polyribosomes during both developmental systems were recorded. These changes were related to changes in levels and syntheses of soluble and particulate proteins. Activities of enzymes intimately involved in these relationships, namely RNAses, ATPases, phosphatases, pyrophosphatases and phosphodiesterases were monitored during development. The metabolic status was further examined by the study of the polypeptide - synthesizing capacity of the ribosomes at different stages as revealed in wheatgerm- derived cell-free systems. Three phases of increased metabolism were apparent in both developmental systems but only the initial and final phases involved increased RNA synthesis which was correlated with increased protein synthetic capacity. Work involving "greening-up" and excision showed some similarities to the normal courses of development but also important differences particularly with respect to the magnitude of the response.